FIG. 1 is a diagram showing an architecture of a Policy and Charging Control (PCC) defined by 3rd Generation Partnership Project (3GPP) according to a related art, and as shown in FIG. 1, a PCRF makes a Quality of Service (QoS) and charging policy for usage of a network resource for a service. Control policy making of the PCRF requires combination of service information received from an AF, subscription information received from a Subscription Profile Repository (SPR), a policy configured by an operator and the like. The PCRF transmits a control policy made for the service to a Policy and Charging Enforcement Function (PCEF) or a BBERF for enforcement. Meanwhile, the PCRF may subscribe for a related event of a bearer layer to the PCEF and/or the BBERF to timely perceive the event and modify the control policy when the event occurs to the bearer layer. Moreover, the PCEF and a Traffic Detection Function (TDF) may enforce an Application Detection and Control (ADC) function according to a PCC rule (PCEF) or ADC rule (TDF) issued by the PCRF.
A Proxy-Call Session Control Function (P-CSCF) may be an AF. The P-CSCF may provide for the PCRF service information of an Internet Protocol Multimedia System (IMS), so as to ensure QoS of service access of a user through the IMS. In addition, the P-CSCF may also acquire from the PCRF, related information of a network accessed by current UE, for IMS management, charging and control. At present, an IMS may acquire current position information of a user through a PCC architecture for legal monitoring, charging and service control. However, such a mechanism is only supported by some access networks (for example, a 3GPP access network) at present. When the P-CSCF makes a request for current position information of the UE to the PCRF, the P-CSCF may not know that the UE does not access an access network supporting reporting of the access network information. There is yet no solution to how to process the request after the PCRF receives the request of the P-CSCF. In addition, in consideration of an IP Flow Mobility (IFOM) scenario, FIG. 2 is a diagram showing IFOM according to the related art, and as shown in FIG. 2, multiple service data flows of a user session may be transmitted in different access networks (for example, a voice is transmitted in a 3GPP access network, while a video is transmitted in a Wireless Local Area Network (WLAN)), and there is also yet no solution to the problem of how to report position information to the P-CSCF by the PCRF.
Therefore, in the related art, there exists a problem of application layer processing error caused by incapability of reporting the access network information or low efficiency of reporting access network information.